No, you don't HAVE TO show to feel you are knowledgeable about the breed in order TO breed. The importance of showing under a judge (in ANY sport: Conformation; Obedience; Agility...even if you had a Yorkie that was a demo dog for Schutzhund!) is that you are relying on the JUDGES to let you know and the spectators know that YOU do in fact know your stuff because you are ready to present that in front of the "world" and multiple judges. THEY are the authority figure to let you know that your feeling of being knowledgeable and ready to breed are valid. You may produce what you think is correct is type and is healthy, but everyone has their own "type" and fits the standard loosely at best but is quite healthy.
So, by showing in any sport under MULTIPLE judges, you are just proving to those around you; yourself; and perspective buyers that you do indeed know what your doing and can prove it. That's what the standard was handed to judges for and multiple sports created. Conformation isn't for everyone and I ABSOLUTELY agree that you can show off what you know and are capable of benefiting the breed by showing in a sport more to your liking. These are terriers and they're supposed to be diverse. They're toys second!!